American contract law draws upon centuries of commercial transactions and traces its roots back

various sources of law?primarily to English and American
common law, or judge?made law, and the United States Constitution. How would you explain the relevance of these main sources of American contract law to a
colleague from another country where the laws may differ?

1. What are the main sources of American contract law?

2. What is promissory estoppel and why is it permitted under a contract theory?